1. Field of the Invention
This invention relates to methods and apparatus for applying a coating material such as a photoresist masking material to a substrate such as a semiconductor wafer or glass.
2. Description of the Related Art
Japanese utility model publication No. 60-95979, open to public inspection on Jun. 29, 1985, discloses an automated spin coater which includes an enclosure within which a spinner chuck is supported for rotation by a motor. The spinner chuck has a vacuum table on which a semiconductor wafer is securely held by vacuum action. A photoresist coating material is applied to the semiconductor wafer which is spun to coat it evenly by centrifugal forces.
When a substrate to be coated is of a shape other than round, a coating material is likely to be deposited at corners of the substrate due to wind pressure. Such undesirable deposition or uneven coating on the substrate may subsequently result in malfunctions during further processing or use of the substrate and therefore, may also result in a serious decrease in the yield of acceptably coated substrates.